diff --git a/README.md b/README.md
index f7d116a5a..0ea607c00 100644
--- a/README.md
+++ b/README.md
@@ -85,11 +85,11 @@ Windows users can download a complete binary (including Python) from the
 The simplest way to install and upgrade dosage is with [pipx]. To install the
 newest stable version with all optional features use:
 
-    pipx install --spec dosage[css,dimensions,bash] dosage
+    pipx install --spec dosage[css,bash] dosage
 
 To install the newest development version, use:
 
-    pipx install --spec "dosage[css,dimensions,bash] @ git+https://github.com/webcomics/dosage.git" dosage
+    pipx install --spec "dosage[css,bash] @ git+https://github.com/webcomics/dosage.git" dosage
 
 To upgrade such installations, just run:
 
@@ -100,7 +100,7 @@ To upgrade such installations, just run:
 If you want to run dosage directly from the source code, you should install
 it in "[editable]" mode, preferable in a [virtual environment]:
 
-    pip install -e .[css,dimensions,bash]
+    pip install -e .[css,bash]
 
 You can invoke Dosage directly from the source code as `./dosage`, but this
 mode of operation is discouraged, since dependencies might be missing.
diff --git a/dosagelib/events.py b/dosagelib/events.py
index b5fd0405b..9ce4402e9 100644
--- a/dosagelib/events.py
+++ b/dosagelib/events.py
@@ -1,7 +1,7 @@
 # -*- coding: utf-8 -*-
 # Copyright (C) 2004-2008 Tristan Seligmann and Jonathan Jacobs
 # Copyright (C) 2012-2014 Bastian Kleineidam
-# Copyright (C) 2015-2017 Tobias Gruetzmacher
+# Copyright (C) 2015-2020 Tobias Gruetzmacher
 
 from __future__ import absolute_import, division, print_function
 
@@ -11,6 +11,8 @@ from six.moves.urllib.parse import quote as url_quote
 import codecs
 import json
 
+import imagesize
+
 from . import rss, util, configuration
 from .output import out
 
@@ -134,18 +136,24 @@ class RSSEventHandler(EventHandler):
 
 def getDimensionForImage(filename, maxsize):
     """Return scaled image size in (width, height) format.
-    The scaling preserves the aspect ratio.
-    If PIL is not found returns None."""
+    The scaling preserves the aspect ratio."""
     try:
-        from PIL import Image
-    except ImportError:
+        origsize = imagesize.get(filename)
+    except Exception as e:
+        out.warn("Could not get image size of {}: {}".format(os.path.basename(filename), e))
         return None
-    img = Image.open(filename)
-    width, height = img.size
-    if width > maxsize[0] or height > maxsize[1]:
-        img.thumbnail(maxsize)
-        out.info("Downscaled display size from %s to %s" % ((width, height), img.size))
-    return img.size
+
+    width, height = origsize
+    if width > maxsize[0]:
+        height = max(round(height * maxsize[0] / width), 1)
+        width = round(maxsize[0])
+    if height > maxsize[1]:
+        width = max(round(width * maxsize[1] / height), 1)
+        height = round(maxsize[1])
+
+    if width < origsize[0] or height < origsize[1]:
+        out.info("Downscaled display size from %s to %s" % (origsize, (width, height)))
+    return (width, height)
 
 
 class HtmlEventHandler(EventHandler):
diff --git a/requirements.txt b/requirements.txt
index 5a2e66052..cb2644c82 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,5 @@
 colorama
+imagesize
 lxml
 requests>=2.0
 six
diff --git a/setup.cfg b/setup.cfg
index 8b945f4e4..cd6649a83 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -35,6 +35,7 @@ python_requires = >=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*
 packages = find:
 install_requires =
     colorama
+    imagesize
     lxml
     requests>=2.0
     six
@@ -50,8 +51,6 @@ console_scripts =
 [options.extras_require]
 css =
     cssselect
-dimensions =
-    Pillow
 bash =
     argcomplete
 test =
diff --git a/tox.ini b/tox.ini
index 5c8cca6e8..eaef96120 100644
--- a/tox.ini
+++ b/tox.ini
@@ -20,7 +20,6 @@ deps =
 # Also install extra dependencies for tests.
 extras =
     css
-    dimensions
     test
 
 [testenv:flake8]